How do you go about poses for more mild emotions?

I think a good example of this would be the emotion of surprise.

For example, if someone were to jump out from behind you and yell "Boo!" and startle you, a cartoony drawing may protray you like this (I don't know how to describe it)

However, if you heard a sudden bang or some other strange noise, you're most likely going to be very confused or at worst a bit startled.

So how would you go about drawing that sort of body language? How would I make it look dynamic? Because I'm not sure if there's going to be much going on there.

Try looking at Aaron Blaise’s YouTube channel, or Griz and Norm’s Tumblr as far as free resources go. (There’s undoubtedly a lot more out there)

You’re specifically looking for stuff talking about expressions or “push and pull” as a starting point. This stuff will usually focus on faces, not overall poses because almost no emotions have characteristic poses in real life.

Pair the tutorial material with going through a favorite movie or tv episode. If you have an animated favorite, bonus. Basically you want to practice picking out expressions the live action actors make, and try drawing them. Animated is a bonus because you can compare with live action and see how the artists used reference to develop a range of emotions.

That in real life bit... there’s multiple acting and dance school techniques for conveying emotions in live theatre performance. So many. Every culture that has theatre has at least one. And since that’s almost every culture... that’s a lot. It’s a thing you can study, and it definitely can influence visual art. But it’s not necessarily a good thing to use blindly. It’s super culturally dependent and it only works if the audience knows that particular theatrical language. For an audience that’s unfamiliar, it can look stupid, rehearsed, unfeeling, ugly... it’s a really tricky thing to use. Older animation resources will sometimes bring it up but they’ll make like specific Western European versions are the way it works.

Thank you!